Flow rate control valve

ABSTRACT

Fluid control valve including a valve body and an energizing member. The body is engaged with one end of a rotating shaft and moves along an axial direction of the shaft based on shaft rotation. The body opens and closes a first opening by the outer periphery, and one end comes into contact with and separates from a second opening. The member energizes the body on another end side of the shaft. A portion abutting on the second opening and a flow passage in which a fluid flows are at the one end of the body in the case where the first opening is fully closed. Since a valve-closed position of the body can be secured, and fluid flows in the flow passage, when a low flow rate is controlled, a stable flow rate is secured without closing the second opening which is a suction port in a valve-closed position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Stage Application, which claims thebenefit under 35 U.S.C. § 371 of PCT International Patent ApplicationNo. PCT/JP2015/052103, filed Jan. 27, 2015 which claims the foreignpriority benefit under 35 U.S.C. §119 of Japanese Patent Application No.2014-011985, filed Jan. 27, 2014, the contents of which are incorporatedherein by reference.

TECHNICAL FIELD

The present invention relates to a flow rate control valve whichcontrols a flow rate of a fluid by operating by rotation of a drivingsource such as a motor.

BACKGROUND ART

Conventionally, in a vehicle such as an automobile and a motorcycle, forexample, in the case of an engine in which fuel injection and ignitionare controlled by an electronic controller, an idling speed controlvalve (ISCV) which is another electronically controlled air controlvalve is provided on a side of a throttle valve as an air control valve.The ISCV controls idle-up and stabilize idling when an air condition isoperated. Specifically, for example, the ISCV controls an intake airamount to the engine and controls the engine to keep a target rotationspeed during idling when a vehicle is in an idling state by tighteningthe throttle valve.

The ISCV, for example, includes a stepping motor, a rotating shaft ofthe stepping motor, and a valve body. The stepping motor works as anactuator which actuates a valve. The valve body includes a screwmechanism between the shaft and moves in an axial direction of theshaft. A top side of the shaft is set to a male screw, a nut provided tothe valve is screwed to the male screw, and based on normal/reverserotations of the shaft, a flow rate of intake air to an engine duringidling is controlled when the valve body is moved to an axial directionof the shaft.

A flow rate control valve described in Patent Literature 1 is known asan example of the above-described flow rate control valve. The flow ratecontrol valve is closed by closing both of a discharge port and asuction port by a valve body.

CITATION LIST Patent Literature

Patent Literature 1: JP 2013-96388 A

SUMMARY OF INVENTION Technical Problem

In the above-described conventional flow rate control valve, a suctionport, in addition to a discharge port, is closed by a valve body in avalve-closed state. Therefore, the valve body is pulled toward theoutside of the suction port since atmospheric pressure is changed at thesuction port, a load is likely to be applied to the valve body, and alsoa stable flow rate may not easily secured when the discharge port isslightly closed to control a low flow rate.

However, if the valve body abuts on the suction port in a valve-closedstate, a configuration is simplified, and an accurate position can beeasily obtained.

The present invention is in view of the above circumstances, and anobject of the present invention is to provide a fluid control valvecapable of securing an accurate valve-closed position of a valve bodyand secure a stable flow rate when a low flow rate is controlled withoutclosing a suction port in a valve-closed state.

Solution to Problem

To achieve the above-described object, a fluid control valve accordingto the present invention includes a body, a rotating shaft, a valvebody, and an energizing member. The body includes a first openingthrough which a fluid passes and a second opening through which a fluidpasses. The rotating shaft is rotatable in normal and reverse directionsby a driving source. The valve body is engaged with one end of therotating shaft. By moving along an axial direction of the rotating shaftbased on rotation of the rotating shaft, the valve body opens and closesthe first opening by an outer periphery, and one end of the valve bodycomes into contact with and separates from the second opening. Theenergizing member energizes the valve body on another end side of therotating shaft. An abutting portion abutting on the second opening and aflow passage in which a fluid flows are provided at the one end of thevalve body in the case where the first opening is fully closed by theouter periphery of the valve body.

In the present invention, in the case where the first opening, which isa discharge port, is closed, the rotating shaft rotates, and the valvebody is moved in an axial direction of the rotating shaft. The firstopening is closed by the outer periphery of the valve body, and anabutting portion provided to one end of the valve body abuts on thesecond opening which is a suction port. Consequently, an accuratevalve-closed position of the valve body can be secured.

Further, even if the abutting portion of the valve body abuts on thesecond opening, a flow passage is provided to one end of the valve body,and a fluid flows in the flow passage. Therefore, when a low flow rateis controlled, a stable flow rate can be secured without closing thesuction port in a valve-closed state.

In the above-described configuration of the present invention, aplurality of the abutting portions are provided in a circumferentialdirection of the valve body at predetermined intervals, and the flowpassage is provided between the abutting portions adjacent to each otherin a circumferential direction.

According to such a configuration, in a valve-closed state, abuttingportions provided in a circumferential direction of a valve body atpredetermined intervals abut on the second opening. Therefore, anaccurate valve-closed position can be easily secured, and a fluid flowsin a flow passage provided between abutting portions adjacent to eachother in a circumferential direction. Consequently, when a low flow rateis controlled, a stable flow rate can be certainly secured withoutclosing a suction port in the valve-closed state.

In the above-described configuration of the present invention, theabutting portion preferably includes an inclined surface which inclineson an axial side of the valve body as moving on one end side of thevalve body and abuts on the second opening.

According to such a configuration, the inclined surface abutting on thesecond opening is provided to the abutting portion, and therefore, evenif a diameter of the second opening is varied, the inclined surfacecertainly abuts on the second opening, and an accurate valve-closedposition of the valve body can be certainly secured.

Further, since the inclined surface is formed to the abutting portion,the abutting portion can be inserted into the second opening. Therefore,a moving amount of the valve body can be increased without enlarging thevalve body, and a control width of the valve body can be increased evenif the valve body is downsized.

Further, in the above-described configuration of the present invention,an abutting portion abutting on one end of the rotating shaft isprovided in the case where the valve body is moved on another end sidein an axial direction of the rotating shaft, and the first opening isfully opened by the outer periphery of the valve body.

According to the above-described configuration, even if the firstopening is fully opened by the outer periphery of the valve body, theabutting portion of the valve body abuts on one end of the rotatingshaft. Therefore, an accurate valve-closed position of the valve bodycan be certainly secured.

Advantageous Effects of Invention

According to the present invention, a first opening is closed by anouter periphery of a valve body, and an abutting portion provided to oneend of the valve body abuts on the second opening which is a suctionport. Accordingly, an accurate valve-closed position of the valve bodycan be secured. Further, even if the abutting portion of the valve bodyabuts on the second opening, a flow passage is provided to one end ofthe valve body, and a fluid flows in the flow passage. Therefore, when alow flow rate is controlled, a stable flow rate can be secured withoutclosing the suction port in a valve-closed state.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates an example of a flow rate control valve according tothe present invention and is a longitudinal sectional view of the flowrate control valve in a valve-open state.

FIG. 2 illustrates an example of the flow rate control valve accordingto the present invention and is a longitudinal sectional view of theflow rate control valve in a valve-closed state.

FIGS. 3(a) and 3(b) illustrate an example of the flow rate control valveaccording to the present invention, FIG. 3(a) is a perspective view of avalve member which is partially cut off, and FIG. 3(b) is a back view ofthe valve member.

FIG. 4 illustrates an example of the flow rate control valve accordingto the present invention and is a perspective view of a moving member.

FIG. 5 illustrates an example of the flow rate control valve accordingto the present invention and is a perspective view of a regulatingmember provided to a motor case.

FIG. 6 illustrates an example of the flow rate control valve accordingto the present invention and is a perspective view illustrating a motorand the moving member in which the valve member is attached.

DESCRIPTION OF EMBODIMENT

Hereinafter, an embodiment of the present invention will be describedwith reference to drawings. In the description below, descriptionsregarding a vertical direction such as an upper end and a lower end arefor simplifying an understanding in the drawings and are not forlimiting such as a mounting attitude of a flow rate control valve.

FIGS. 1 and 2 are a sectional view illustrating an example of a flowrate control valve according to the present invention. As illustrated inFIGS. 1 and 2, the flow rate control valve includes a body 100, a motoras a driving source (stepping motor) 101, and a valve body 102.

The body 100 is formed in a cylindrical shape, and a cylindrical motormounting portion 103 and a cylindrical valve body mounting portion 104are consecutively provided in an axial direction in the body 100. Thecylindrical motor mounting portion 103 mounts a motor 101. A diameter ofthe cylindrical valve body mounting portion 104 is smaller than adiameter of the motor mounting portion 103.

The motor 101 is provided in a motor case 105. The inside of the motorcase 105 is formed in a cylindrical hollow columnar shape, and on aninner peripheral surface side of the motor case 105, annular two coils101 a along the inner peripheral surface are provided back and forthalong an axial direction as a stator of the motor 101. The coil 101 a issupported by a coil support member 101 c in a state in which the coil101 a is wound around a coil bobbin 101 b.

On an inner side of the annular coil 101 a, a rotor 101 e is provided inwhich a cylindrical magnet 101 d is fixed on an outer periphery. Therotor 101 e rotates around a stator, a stator and a rotor form a motor,and the rotor 101 e including the magnet 101 d is rotated by anelectromagnetic force.

Further, the inside of the rotor 101 e is formed in a cylindrical hollowcolumnar shape, and a projecting portion 101 f is formed at one end(lower end) of the rotor 101 e, and a through hole is formed at theprojecting portion 101 f. A rotating shaft 106 which is a rotating axisof a rotor is inserted through the through hole, and the rotating shaft106 is fixed. Further, one end (lower end) of the rotor 101 e isprojected in a flange shape on an outer peripheral side, and one endside of the cylindrical magnet 101 d is positioned. An outer peripheralsurface of the flange-like portion and an outer peripheral surface ofthe magnet 101 d have a substantially same size outer diameter and arecoaxially arranged.

The rotating shaft 106 is a round rod member. If a tip of the projectingportion 101 f of the rotor 101 e is a substantial center, one end side(lower end side) is extended in the body 100 from the motor case 105.Further, another end side (upper end side) of the rotating shaft 106 isdisposed on an inner side of the rotor 101 e.

Furthermore, a male screw 106 a is formed on an outer peripheral surfaceof one end side of the rotating shaft 106. Here, a portion other thanthe male screw 106 a is a shaft 106 b.

In the rotating shaft 106, a diameter of the male screw 106 a is largerthan a diameter of the shaft 106 b, and the male screw 106 a has a widershape than other portions of the rotating shaft 106. A female screw 114a of the valve body 102 is screwed to the male screw 106 a as describedbelow.

Further, a center of the rotating shaft 106 is supported by a projectingportion 101 f, and the projecting portion 101 f is rotationallysupported by a bearing 107 of the motor case 105. In FIG. 1, the bearing107 is integrally illustrated with the motor case 105. However, thebearing 107 may be separated from the motor case 105.

Further, another end (upper end) of the rotating shaft 106 is disposedon an inner side of the rotor 101 e as described above and rotationallysupported by a shaft support portion 108. The shaft support portion 108functions as a sliding bearing and also functions as a radial bearingand a thrust bearing. Specifically, the rotation center of the rotatingshaft 106 is regulated by the shaft support portion 108, and alsomovement in a direction from one end to another end of the rotatingshaft 106 along an axial direction of the rotating shaft 106 isregulated. Movement in an opposite direction is regulated by acompression coil spring 122 as an energizing member as described later.

The male screw 106 a provided at one end of the rotating shaft 106 isscrewed to the valve body 102, and the valve body 102 opens and closes afirst opening 110, through which a fluid passes, by moving in an axialdirection of the rotating shaft 106 based on rotation of the rotatingshaft 106. The first opening 110 is formed by an opening disposed at aninner side end of a through hole 109 penetrating from an innerperipheral surface to an outer peripheral surface of the valve bodymounting portion 104 of the body 100.

A plurality of the through holes 109 and the first openings 110 areprovided in a circumferential direction of the body 100 at predeterminedintervals. Further, the first openings 110 are opened and closed by thevalve body 102.

The valve body 102 includes a valve member 111 and a moving member 112.

The valve member 111 is formed in a cylindrical shape as illustrated inFIG. 3(a), and an outer peripheral surface thereof is slidinglycontacted to an inner peripheral surface of the valve body mountingportion 104 (refer to FIGS. 1 and 2). Therefore, the first opening 110is opened and closed by an outer peripheral surface (outer periphery) ofthe valve member 111.

Further, one end of the valve member 111 is circularly opened, and adisk-shaped closing plate 111 a is provided to another end. Asillustrated in FIG. 3(b), the round-shaped through hole 111 b is formedat the center of the closing plate 111 a. Further, four rectangularthrough holes 111 c radially disposed with respect to the through hole111 b are formed on the closing plate 111 a. These four through holes111 c are disposed in a circumferential direction at equal intervals.

Further, as illustrated in FIG. 3(a), four ribs 113 are projected in acircumferential direction at equal intervals on aback surface of theclosing plate 111 a. The rib 113 includes a circular-arc peripheral wallportion 113 a and linear wall portions 113 b and 113 b formed on bothends of the peripheral wall portion 113 a. Inner peripheral surfaces ofthe four peripheral wall portions 113 a of the four ribs 113 areconsecutively formed with an inner peripheral surface of theround-shaped through hole 111 b in an axial direction, and surfaces ofthe wall portions 113 b and 113 b facing in a circumferential directionare consecutively formed with surfaces of the rectangular through holes111 c facing in a circumferential direction, in an axial direction.

As illustrated in FIG. 4, the moving member 112 includes a cylindricalmain body 114, an abutting portion 115 provided at one end of the mainbody 114, and a regulating portion 116 provided at another end of themain body 114.

As illustrated in FIGS. 1 and 2, the female screw 114 a is formed on aninner peripheral surface of a cylindrical hole in the main body 114, anda male screw 106 a, which is an end of the rotating shaft 106, isscrewed to the female screw 114 a. An end of the hole in which thefemale screw 114 a is formed is closed and becomes an abutting surface(abutting portion) 114 b, and one end surface of the rotating shaft 106can abut on the abutting surface 114 b.

Further, an outer diameter of the main body 114 is almost same as orslightly smaller than an inner diameter of the through hole 111 bprovided to the closing plate 111 a of the valve member 111. Therefore,the main body 114 can be inserted into the valve member 111 through thethrough hole 11 b.

In the case where the first opening 110 is fully closed by an outerperiphery of the valve member 111, the abutting portion 115 abuts on asecond opening 118 to be described later, and the valve body 102 in avalve-closed state is positioned. Further, the abutting portion 115includes a locking portion 115 a on which the rib 113 of the valvemember 111 abuts and by which the valve member ill is prevented fromcoming off from the moving member 112.

As illustrated in FIG. 4, four abutting portions 115 are provided at oneend of the main body 114 in a circumferential direction at equalintervals, and four flow passages 117 are provided at equal intervals ina circumferential direction between abutting portions 115 and 115adjacent to each other in the circumferential direction. The abuttingportion 115 is formed by cutting off a prefix conical portion providedat a tip of the main body 114 by a part of the flow passage 117, and theabutting surface (locking surface) 115 a facing on the regulatingportion 116 side of the abutting portion 115 can abut on the rib 113.

Further, the abutting portion 115 is formed in a size capable of passingthrough the rectangular through hole 111 c formed on the closing plate111 a of the body 100, and the surface of the abutting portion 115,which faces on the regulating portion 116 side and is orthogonal to themain body 114, is the locking portion 115 a (abutting surface).Therefore, when the main body 114 rotates at 45° around an axis afterthe abutting portion 115 has passed through the through hole 111 c, thelocking portion 115 a of the abutting portion 115 can abut on the rib113.

Further, an inclined surface 115 b inclined with respect to an axis ofthe main body 114 of the abutting portion 115 is inclined so as toapproach on an axial side of the main body 114 (valve body 102) asmoving on one end side of the main body 114 (valve body 102).

Further, as illustrated in FIGS. 1 and 2, a through hole (suction hole)119 is provided at a center of the closing plate provided at one end(lower end) of the body 100, and the first opening 118 is provided at anopening edge of an inner side end of the suction hole 119.

The inclined surface 115 b of each of the four abutting portions 115 canabut on the first opening 118. Specifically, one end of the movingmember 112 is inserted into the suction hole 119, and the inclinedsurface 115 b abuts on the first opening 118. Consequently, furthermovement of the moving member 112 is regulated. Therefore, the inclinedsurface 115 b is a stopper surface for regulating movement of the movingmember 112, and accordingly the valve body 102 in a valve-closed stateis positioned.

Further, in a state in which the inclined surface 115 b abuts on thefirst opening 118, the flow passage 117 is provided between the firstopening 118 and the main body 114, and a fluid (air) can flow throughthe flow passage 117.

The regulating portion 116 abuts on the valve member 111 and regulatesmovement of the valve member 111 to another end side of the rotatingshaft 106. As illustrated in FIG. 4, four regulating portions 116 areprovided in a circumferential direction at equal intervals by cuttingoff four portions of a disk-shaped flange portion, which is provided atanother end of the main body 114, in a circumferential direction atequal intervals in a rectangular shape each, and a notch 120 is formedbetween the regulating portions 116 and 116 adjacent to each other in acircumferential direction.

The notch 120 is provided on an extension line in an axial direction ofthe flow passage 117, and a shape and a size of the notch 120 aresubstantially same as four rectangular through holes 111 c provided onthe closing plate 111 a of the valve member 111.

The locking portion 115 a of the abutting portion 115 can abut on therib 113 by rotating the main body 114 around an axis at 45° after theabutting portion 115 has passed through the through hole 111 c of thevalve member 111. Further, the rectangular through hole 111 c and thenotch 120 are overlapped in an axial direction of the moving member 112,and the regulating portion 116 can abut on the closing plate 111 a ofthe valve member 111 between the rectangular through holes 111 c and 111c adjacent to each other in a circumferential direction. Therefore,movement of the rotating shaft 106 of the valve member 111 to anotherend side can be regulated by the regulating portion 116.

Further, as illustrated in FIGS. 1 and 2, in the body 100, a regulatingmember 121 is provided which is engaged with the valve body 102 andregulates rotation of the valve body 102 around an axis. Specifically,four columnar regulating members 121 are provided in a circumferentialdirection at equal intervals on a disk 105 a fixed on another endsurface of the motor case 105 as illustrated in FIG. 5. The regulatingmembers 121 extend to the valve body mounting portion 104 in parallelwith the rotating shaft 106 (refer to FIGS. 1 and 2) and disposed atequal intervals in a circumferential direction on an outer peripheralside of the projecting portion 101 f in which the rotating shaft 106 isinserted.

Further, a sectional shape of the regulating member 121 almost same asor slightly smaller than the rectangular through hole 111 c and 120, andin the case where the through hole 111 c and the notch 120 areoverlapped in an axial direction of the moving member 112, theregulating member 121 is inserted into the through hole 111 c and thenotch 120 and engaged with the valve member 111 and moving member 112,specifically engaged with the valve body 102. The regulating member 121is fixed to the motor case 105 via the disk 105 a and therefore canregulate rotation of the valve body 102 around an axis.

As illustrated in FIG. 6, a length of the regulating member 121 is setsuch that a lower end of the regulating portion 121 can be inserted intothe four through holes 111 c of the valve member 111 in the case wherethe moving member 112 moves upward, and a lower end surface of therotating shaft 106 abuts on the abutting surface 114 b in the movingmember 112 (in the case where the moving member 112 is closest to themotor 101). Therefore, in such a state, rotation of the valve member 111around an axis is regulated by the regulating member 112, and the rib113 of the valve member 111 abuts on the locking portion 115 a of themoving member 112. Consequently the valve member 111 is prevented fromcoming off from the moving member 112, specifically from the motor 101.

Further, as illustrated in FIGS. 1 and 2, the compression coil spring(energizing member) 122 is provided on one end side (lower end side) inthe body 100, in other words, to the valve body mounting portion 104.One end (lower end) of the compression coil spring 122 is disposedaround the suction port 118 on a bottom surface of the valve bodymounting portion 104, and another end (lower end) thereof is insertedinto the cylindrical valve member 111 and compressed on an outer side ofthe rib 113 on a back surface of the closing plate 111 a of the valvemember 111. Therefore, the valve member 111 is energized on another endside (lower end side) of the rotating shaft 106 by the compression coilspring 122.

As illustrated in FIG. 1, a state in which the valve body 102 ispositioned on an upper side, and one end surface (lower end surface) ofthe rotating shaft 106 abuts on the abutting surface 114 b on a lowerend of a hole in which the female screw 114 a of the moving member 112is provided is a valve-open position in which the first opening 110 ofthe discharge hole 109 is opened. As illustrated in FIG. 2, a state inwhich the valve body 102 is positioned on a lower side, and the inclinedsurface 115 b on one end (lower end) of the moving member 112 abuts onthe second opening 118 of the suction hole 119 is a valve-closedposition in which the second opening 118 is closed.

In the case where the valve body 102 is assembled to the motor 101,first the female screw 114 a of the moving member 112 is screwed to themale screw 106 a provided at one end (lower end) of the rotating shaft106 of the motor 101. Accordingly, the moving member 112 is engagingwith the rotating shaft 106, and four regulating members 121 areinserted into four notches 120 provided at another end of the movingmember 112. Rotation of the moving member 112 is regulated by theregulating member 121.

In this case, by operating the motor 101 and rotating the rotating shaft106 in a normal direction, a predetermined length of the male screw 106a of the rotating shaft 106 is screwed to the female screw 114 a of themoving member 112.

Next, the moving member 112 is inserted into the valve member 111.Conversely, the valve member 111 is fitted outside of the moving member112.

In this case, four through holes 111 c of the valve member 111 arefitted to four abutting portions 115 of the moving member 112 in acircumferential direction, and the moving member 112 is inserted in tothe valve member 111. Therefore, the abutting portions 115 pass throughthe through holes 111 c, and the main body 114 passes through thethrough hole 111 b.

Then, in the case where the abutting portions 115 pass through thethrough holes 111 c and pass by the rib 113, the moving member 112 (mainbody 114) is rotated around an axis at 45°. Accordingly, the lockingportion 115 a of the abutting portion 115 faces the rib 113 of the valvemember 111 and can abut on the rib 113, and the regulating member 121matches to the through hole 111 c of the valve member 111 in acircumferential direction.

Next, the regulating member 121 is inserted into the through hole 111 cby further inserting the moving member 112 into the valve member 111(fitting the valve member 111 to the outside of the moving member 112).Consequently, rotation of the valve member 111 is regulated.

In this state, by operating the motor 101 again and rotating therotating shaft 106 in a normal direction, one end surface (lower endsurface) of the rotating shaft 106 is abutted on the abutting surface114 b in the moving member 112 as illustrated in FIG. 6.

In such a state, rotation of the valve member 111 around an axis isregulated by the regulating member 112, and the rib 113 of the valvemember 111 abuts on the locking portion 115 a of the moving member 112and is prevented from coming off from the moving member 112,specifically from the motor 101.

Next, the compression coil spring 122 is inserted into the valve bodymounting portion 104 of the body 100 and disposed on a bottom surface ofthe valve body mounting portion 104.

Next, the valve body 102 including the moving member 112 and the valvemember 111 prevented from coming off from the moving member 112 ismounted to the valve body mounting portion 104, and an upper end of thecompression coil spring 122 abuts on the closing plate 111 a of thevalve member 111. In this state, the compression coil spring 122 is notcompressed.

As the valve body 102 is mounted in the valve body mounting portion 104,the valve member 111 is moved by pushing to the upper side (another endside of the rotating shaft 106) by the compression coil spring 122. Inthis case, the compression coil spring 112 is slightly compressed by theown weight of the valve member 111.

When the valve member 111 moves upward by a predetermined distance, thevalve member 111 abuts on the regulating portion 116 of the movingmember 112, and further movement of the valve member 111 to the upperside (another end side of the rotating shaft 106) is regulated.

Further, as the valve member 111 moves upward, one end surface (lowerend surface) of the regulating member 121 is positioned lower than oneend surface (lower end surface) of the valve member 111.

The compression coil spring 122 is fully extended at a position wherethe valve member 111 is moved upward by a predetermined distance fromthe position where the discharge hole 110 formed to the body 100 isfully opened. Therefore, a predetermined amount of the compression coilspring 122 is compressed by moving down the valve body 102 with themotor case 105 by a predetermined distance from this state. In thiscase, the valve body 102 is moved downward such that the discharge hole110 is not closed by the valve member 111.

After that, the valve body 102 is assembled to the motor 101 by fixingthe motor case 105 to the motor mounting portion 103. In such a state,the valve body 102 is always energized upward by the compression coilspring 122. The rotating shaft 106 is screwed to the moving member 112of the valve body 102. Therefore, the upward energizing force is appliedto the rotating shaft 106 and further to the shaft support portion 108.

In such a flow rate control valve, the valve body 102 (valve member 111)opens the first opening 110 of the discharge hole 109 when the engine isin an idling state. Specifically, as illustrated in FIG. 2, in the casewhere the valve body 102 is at a valve-closed position, the rotatingshaft 106 is rotated in a normal direction by the motor 101. By screwfeeding actions of the male screw 106 a of the rotating shaft 106 andthe female screw 114 a of the moving member 112, the moving member 112starts moving upward in an axial line direction, and the valve member111 starts moving upward with the moving member 112 (at the same timingwith the moving member 112). Then, as illustrated in FIG. 1, an outerperipheral surface of the valve body 102 opens the first opening 110.

In this case, the moving member 112 moves upward until the abuttingsurface 114 b of a hole, in which the female screw 114 a is formed,abuts on one end surface (lower end surface) of the rotating shaft 106,and rotation of the rotating shaft 106 by the motor 101 is stopped whenthe abutting surface 114 b abuts on the end surface. Then, one end(lower end) of the moving member 112 completely is separated from thefirst opening 118 of the suction hole 119, and the first opening 118 isfully opened.

Then, air introduced to the suction hole 119 through a piping from asurge tank on an upstream side from a throttle valve flow into the valvebody mounting portion 104, is discharged from the discharge hole 110,and flows into an engine.

On the other hand, when the engine is not in an idling state, asillustrated in FIG. 1, the rotating shaft 106 is rotated in a reversedirection by the motor 101, and the valve body 102 (valve member 111)closes the first opening 110 of the discharge hole 109 in the case wherethe valve body 102 is at a valve-open position. Specifically, by a screwfeeding action of the male screw 106 a of the rotating shaft 106 and thefemale screw 114 a of the moving member 112, the moving member 112starts moving downward in an axial line direction, and the valve member111 starts moving downward with the moving member 112 (at the sametiming with the moving member 112). Then, as illustrated in FIG. 2, anouter peripheral surface of the valve member 111 closes the firstopening 110.

In addition, in the valve body 102, further downward movement of themoving member 112 is regulated when the inclined surface 115 b at oneend (lower end) of the moving member 112 abuts on the first opening 118of the suction hole 119 after or at the same time when the valve member111 closes the discharge hole 110.

Further, in a state in which the inclined surface 115 b abuts on thesecond opening 118, the flow passage 117 is provided between the secondopening 118 and the main body 114, and a fluid (air) can flow throughthe flow passage 117.

According to the embodiment, in the case where the first opening 110,which is a discharge port, is closed, the rotating shaft 106 rotates,and the valve body 102 is moved in an axial direction of the rotatingshaft 106. The first opening 110 is closed by the outer periphery of thevalve member 111 of the valve body 102, and the abutting portion 115provided at one end of the moving member 112 of the valve body 102 abutson the second opening 118 which is a suction port. Accordingly, anaccurate valve-closed position of the valve body 102 can be secured.

Further, even if the abutting portion 115 of the moving member 112 abutson the second opening 118, the flow passage 117 is provided to one endof the moving member 112, and a fluid can flow through the flow passage117. Therefore, the flow passage can be secured without closing thesuction port (second opening) 118 in a valve-closed state.

Further, four abutting portions 115 are provided at predeterminedintervals in a circumferential direction of the moving member 112 of thevalve body 102, and the flow passage 117 is provided between theabutting portions 115 and 115 adjacent to each other in thecircumferential direction. Therefore, an accurate valve-closed positionof the valve body can be easily secured, and a fluid flows in the flowpassage 17 provided between the abutting portions 115 and 115 adjacentto each other in the circumferential direction. Consequently, the flowpassage can be certainly secured without closing the suction port(second opening) 118 in a valve-closed state.

Further, the inclined surface 115 b abutting on the second opening 118is formed to the abutting portion 115, and therefore, even if a diameterof the second opening 118 is varied, the inclined surface 115 bcertainly abuts on the second opening 118, and an accurate valve-closedposition of the valve body 102 can be certainly secured.

In addition, since the inclined surface 115 b is formed to the abuttingportion 115, the abutting portion 115 can be inserted into the secondopening 118. Therefore, a moving amount of the valve body 102 can beincreased without enlarging the valve body, and a control width of thevalve body 102 can be increased even if the valve body is downsized.

Further, the abutting surface (abutting portion) 114 b which abuts onone end of the rotating shaft 106 is provided to a hole in the movingmember 112 of the valve body 102 in the case where the valve body 102 ismoved on another end side in an axial direction of the rotating shaft106, and the first opening 110 is fully opened by the outer periphery ofthe valve member 111. Therefore, if the first opening 110 is fullyopened by the outer periphery of the valve member 111, the abuttingsurface (abutting portion) 114 b abuts on one end of the rotating shaft106. Therefore, an accurate valve-closed position of the valve body 102can be secured.

Further, in the case where the valve body 102 is assembled to the motor101, the female screw 114 a of the moving member 112 is screwed to themale screw 106 a on one end of the rotating shaft 106 rotatable by themotor 101. Then, the moving member 112 is inserted in the valve member111, the valve member 111 is abutted on the locking portion 115 a, andthe valve member 111 is prevented from coming off from the moving member112. On the other hand, the compression coil spring 122 is provided tothe valve body mounting portion 104 in the body 100, and the compressioncoil spring 122 is stably held in the body 100. Then, the valve member111 is arranged to the compression coil spring 122, and consequently thevalve body 102 can be easily assembled to the motor 101.

Further, when the valve body 102 is removed, the valve member 111prevented from coming off from the moving member 112 is pulled out fromthe body 100 with the moving member 112 and separated from thecompression coil spring 122, and then the moving member 112 is moveddownward by rotating the rotating shaft 106 by the motor 101.Accordingly, rotation regulation of the valve member 111 by theregulating member 121 is released. Then, by rotating the valve member111 around an axis at 45°, locking of the valve member 111 is released,and the valve member 111 is removed from the moving member 112, and alsothe valve body 102 is easily removed by removing the moving member 121from the rotating shaft 106.

Further, the moving member 112 can be inserted into the valve member111, and by inserting the moving member 112 into the valve member 111and relatively rotating them around an axis at a predetermined angle(45°), the valve member 111 can abut on the locking portion 115 a, andthe valve member 111 is certainly prevented from coming off from themotor 101 when the valve body 102 is assembled to the motor 101.

Furthermore, in the body 100, the regulating member 121 which is engagedwith the valve body 102 and regulates rotation of the valve body 102around an axis is fixed to the motor case 105. Therefore, in the casewhere the rotating shaft 106 rotates in normal and reverse directions bythe motor 101, the regulating member 121 regulates rotation around anaxis of the valve body 102 by being engaged with the valve body 102, andconsequently the valve body 102 can be certainly moved along an axialdirection of the rotating shaft 106.

Further, in the case where the valve member 111 can abut on the lockingportion 115 a and is prevented from coming-off from the moving member112, the regulating member 121 regulates rotation of the valve member111 around an axis, and the valve member 111 is certainly prevented fromcoming off from the moving member 112.

REFERENCE SIGNS LIST

-   100 body-   101 motor-   102 valve body-   106 rotating shaft-   106 a male screw-   110 first opening-   114 a female screw-   114 b abutting surface (abutting portion)-   115 abutting portion-   117 flow passage-   118 second opening-   122 compression coil spring (energizing member)

The invention claimed is:
 1. A flow rate control valve, comprising: abody including a first opening through which a fluid passes and a secondopening through which a fluid passes; a rotating shaft rotatable innormal and reverse directions by a driving source; a valve body engagedwith one end of the rotating shaft, the valve body which opens andcloses the first opening by an outer periphery and of which one endcomes into contact with and separates from the second opening, by movingalong an axial direction of the rotating shaft based on rotation of therotating shaft; and an energizing member configured to energize thevalve body on another end side of the rotating shaft, wherein anabutting portion abutting on the second opening and a flow passage inwhich a fluid flows are provided to the one end of the valve body in acase where the first opening is fully closed by the outer periphery ofthe valve.
 2. The flow rate control valve according to claim 1, whereina plurality of the abutting portions are provided in a circumferentialdirection of the valve body at predetermined intervals, and the flowpassage is provided between adjacent abutting portions in thecircumferential direction.
 3. The flow rate control valve according toclaim 2, wherein the abutting portion includes an inclined surface whichinclines on an axial side of the valve body as moving on one end side ofthe valve body and abuts on the second opening.
 4. The flow rate controlvalve according to claim 1, wherein an abutting portion which abuts onone end of the rotating shaft is provided in a case where the valve bodymoves on another end side in an axial direction of the rotating shaft,and the first opening is fully opened by the outer periphery of thevalve body.
 5. The flow rate control valve according to claim 2, whereinan abutting portion which abuts on one end of the rotating shaft isprovided in a case where the valve body moves on another end side in anaxial direction of the rotating shaft, and the first opening is fullyopened by the outer periphery of the valve body.
 6. The flow ratecontrol valve according to claim 3, wherein an abutting portion whichabuts on one end of the rotating shaft is provided in a case where thevalve body moves on another end side in an axial direction of therotating shaft, and the first opening is fully opened by the outerperiphery of the valve body.